CHICAGO - The Alexi for Illinois campaign launched a new Web ad today, challenging Republican Congressman Mark Kirk to stop hiding and start answering questions about why he wants to oppose President Obama and lead the effort to repeal health care reform. His absence on the issue is revealing since Congressman Kirk was one of the first to sign the Club For Growth's pledge to repeal health care reform back in January - one month before the bipartisan health care summit, and two months before a bill was available to read.